in multiplayer, it depends on the weapon set you choose(e.g. you can't get 2 k40s in the sniping weapon set). The weapon set is Pheonix weapons. I know how you can get 2 k40s again and again in fort knox multiplayer scenario: When you start, go to the place where you can climb alot of stairs. Then keep going down the stairs until you reach the very bottom. then get a k40( i dont remember if you start with one but if you do, it just makes things easier) and then wait for another one if you dont have another k40. when it reappears, you've got 2 k40s. you can do this for all the other scenarios as long as your weapon set is Pheonix weapons.